Gallbladder Cancer Surgery in the United States: Lymphadenectomy Trends and Impact on Survival.

Background: Gallbladder cancer has a poor prognosis, and surgery is the only curative treatment. However, lymphadenectomy has been underperformed. We evaluate the trend of lymphadenectomy in the United States and its impact on survival.

Methods: This is a cohort study of patients who underwent gallbladder cancer surgery between 2004 and 2016. Trend analysis of the rate of lymphadenectomy and the number of lymph nodes (LNs) removed were examined. The impact of lymph node status and different LN staging systems on survival was examined.

Results: Of the 4577 patients identified, 69.9% were female, the mean age was 71.0 (±12.4), 87.2% had ≥ T2, and only 50.3% (n = 2302) received lymphadenectomy. Although the rate of lymphadenectomy and the number of LNs removed increased during the study period, both with P < 0.0001, the rate of patients who received examination of ≥6 LNs remained low, 13.6% in 2016. Adjusted regression analysis showed that patients without LN examination had worse overall survival than patients with LN positive disease, HR: 1.11 (95% CI: 1.01, 1.22). Concordance index analysis revealed that LN ratio (LNR) and Log odds of positive LN (LODDS) did not improve the ability of the American Joint Commission on Cancer (AJCC) staging in predicting 5-y survival rate.

Conclusions: Lack of LN examination is associated with worse survival than LN positive disease. Although the rate of LN examination and number of LNs retrieved have increased from 2004 to 2016, they remained low. LNR and LODDS staging systems added no benefit to AJCC staging ability in predicting a 5-y survival rate.